Many industries and applications use storage batteries. Power utilities, transportation companies, alternative energy companies, data centers, banks, office complexes, etc. use storage batteries to backup a primary power source. For example, communications and computing equipment in telecommunication central offices, datacenters, and wireless network cell sites use a direct current (DC) power source, typically −48V or −24V. Typically, the commercial alternating current (AC) power feed that supplies a site is converted to DC to appropriately match the requirements of the individual equipment.
Because commercial AC power is not always reliable enough for mission critical systems, it is common to provide backup power in the event of a failure of the commercial feed. The backup power is typically provided by a collection of power sources or electrochemical batteries, known as a battery plant. The batteries may be located within the site and coupled with power distribution bars, to feed DC equipment, and with inverters, to feed AC equipment. The batteries may be located within an uninterruptible power supply (UPS). Regardless of where the batteries are located, they are often oriented in groups, wired in series up to a required voltage.
In order to obtain the maximum battery run-time and life expectancy, it is necessary to perform periodic maintenance tests. These tests are commonly performed by maintenance personnel who travel to the remote site. Using complex and expensive equipment, the personnel take measurements and readings from the batteries. This work is made more difficult when the batteries are located in areas with electromagnetic noise, such as that emitted by the equipment being powered. In order to increase battery plant reliability and lower maintenance costs, it is desirable to perform these tests in a manner that minimizes measurement errors and perhaps without the need to physically dispatch maintenance personnel.